PayPal\PayPalAPI\DoDirectPaymentReq::toXMLString PHP Method

    public function toXMLString()
    {
        $str = '';
        $str .= '<ns:DoDirectPaymentReq>';
        if ($this->DoDirectPaymentRequest != null) {
            $str .= '<ns:DoDirectPaymentRequest>';
            $str .= $this->DoDirectPaymentRequest->toXMLString();
            $str .= '</ns:DoDirectPaymentRequest>';
        }
        $str .= '</ns:DoDirectPaymentReq>';
        return $str;
    }